Thanks in advance for any tips on my ongoing pass. side misfires. I have read through these forums and found many tips but nothing so far has changed my CL600s misfires.
Some details

• Im the second owner and purchased the vehicle in 2017 with 74K miles
• No previous issues with misfires
• Problem occurred out of no where, low rpm and CEL popped a P0300, 301, 302 only
• Then at WOT it pops P0301,302, 307,308,311, 312 and at times...some random codes like seat adjustment, P0600 comm loss, right rear window sensors, just totally random
• Battery is one year old OEM from Mercedes
• Always been a California car, so low moisture, no rust
• No recent service work

When I clear the CEL and drive the car lightly, after approx 10 miles the CEL comes back with ONLY a P0300,P0301,P0302 an never gets any worse, no other codes no limp mode drives normal.
If I WOT i get about 5 seconds of solid pull till redline, then numerous right side misfires occur along with a few "pd" protection codes and limp mode.

What have i done

• did first plug change in 107K miles
• replaced passenger side coil pack
• replaced Voltage Transformer
• replaced spark plug boots
• 2x checked all my work
• found TIB that a solder connection midway up wiring harness near air intake can become corroded and to resolder. Did that
• Replaced fuel filter as never been done

none of the above made any changes

 

SOLVED

To 100% repair the multi-misfires it required...

• Both Coilpacks
• 24 x NGK plugs + Boots

Total $3000 + about 8 hours labor + several ounces of Balvenie 12 year scotch